Quantum dots (QDs) can also be called nanocrystals, and are nanoparticles consisting of II-VI family or III-V family elements. The particle sizes of quantum dots are generally between 1 nm˜20 nm. Because electrons and holes are confined by quantum, the structure of continuous energy bands is converted into the structure of discrete energy bands, and thus quantum dots may emit fluorescence after excitation.
The emission spectra of quantum dots can be controlled by altering the sizes of the quantum dots. By altering the sizes and chemical compositions of quantum dots, their emission spectra can be made to cover the whole visible region. Using CdTe quantum dots as an example, when the particle sizes grow from 2.5 nm to 4.0 nm, the emission wavelength can make a red shift from 510 nm to 660 nm.
Currently, the light emitting property of quantum dots can be utilized so as to employ quantum dots as molecular probes in fluorescent labeling. They can also be used in a display device. Where monochromatic quantum dots are used as the light source of the backlight module of a liquid crystal display panel, after excited by a blue light emitted by LED, the monochromatic quantum dots emit monochromatic light which mixes with the blue light to form white background light, which has large light gamut and can improve the graphic quality. However, in the prior art, there has been no design to apply the quantum dots within the liquid crystal display panel.